Question: Express your answer as a mixed number simplified to lowest terms. $15\dfrac{2}{8}-4\dfrac{15}{20} = {?}$
Solution: Simplify each fraction. $= {15\dfrac{1}{4}} - {4\dfrac{3}{4}}$ Find a common denominator for the fractions: $= {15\dfrac{1}{4}}-{4\dfrac{3}{4}}$ Convert ${15\dfrac{1}{4}}$ to ${14 + \dfrac{4}{4} + \dfrac{1}{4}}$ So the problem becomes: ${14\dfrac{5}{4}}-{4\dfrac{3}{4}}$ Separate the whole numbers from the fractional parts: $= {14} + {\dfrac{5}{4}} - {4} - {\dfrac{3}{4}}$ Bring the whole numbers together and the fractions together: $= {14} - {4} + {\dfrac{5}{4}} - {\dfrac{3}{4}}$ Subtract the whole numbers: $=10 + {\dfrac{5}{4}} - {\dfrac{3}{4}}$ Subtract the fractions: $= 10+\dfrac{2}{4}$ Combine the whole and fractional parts into a mixed number: $= 10\dfrac{2}{4}$ Simplify to lowest terms: $= 10\dfrac{1}{2}$